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Hats on a death row!! One of my favorites puzzles!
Posted 22 November 2011 - 12:34 AM
Posted 23 November 2011 - 05:42 PM
Edited by plainglazed, 23 November 2011 - 11:42 PM.
Posted 09 December 2011 - 07:49 AM
I would love to get some feedback on my solution:
The first guy that is being asked, simply tells the color of the man in front of him, if he is lucky he lives, if not, oh well he did it for the team.
Now, the next guy has already heard his color (black or red) and he is guaranteed freedom, but to help the next guy, here is my idea
If his color matches the one in front, he says the color without hesitation, if it's different, he pauses and thinks and then says his color.
The next guy listening, will consider the pause as a negation of the prevoius color and continue this process ...
Good one ?
Posted 13 December 2011 - 12:38 PM
Your reasoning is correct. It was stated that a correct strategy would guarantee the safety of 19 of the 20, with the 20th (first to guess) having a 50% chance.
With no other information present, I don't see how this is solvable. What strategy would allow you to say the word "red" or the word "black" and tell nineteen people which of two colors each was wearing? I believe it is impossible; you cannot convey that much information in a simple binary choice.
I can see a method to save at least 13 of the 20 people:Spoiler for solution
I see but knowing prisoners.....
Posted 03 January 2012 - 06:46 PM
Posted 04 January 2012 - 03:23 PM
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20
Prisoner 20 will start first. Since he can see everyone in front of him, he knows and will shout the color of his hat (if he sees 9 black 10 red that means he is wearing black, and vice versa)
Prisoner 19 will also be able to shout the color of his hat (if he sees 9 black 9 red and prisoner 20 shouted black, that means he is wearing red)
Prisoners 18 to 2 repeat the same steps.
Prisoner 1 having heard all the color shouted before his turn will also know his color (if 9 shouted black and 10 shouted red that means he is black)
Posted 05 January 2012 - 03:11 PM
one wrong timing and all are gone !!
Here's my solution, not sure if it's allowed or not...Spoiler for Here's my solution.. probably something wrong with it...
How's this one?
Posted 07 January 2012 - 02:16 AM
2.You all say the same color and hope your right
Posted 13 June 2012 - 05:38 PM
but the slightest mistake and all would be executed
Edited by vivekkumarjha, 13 June 2012 - 05:39 PM.
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